嵌入式Linux终端上VoIP与H.264视频传输的设计

发布时间：2018-06-06 15:02

本文选题：维修辅助设备 + SIP协议　；参考：《电子科技大学》2012年硕士论文

【摘要】：近年来,随着嵌入式平台软硬件技术的飞速发展,我国的飞机维修辅助设备功能得到了持续的扩充和强化,各方面的性能也获得了很大的提升,有效的提高了维修人员在飞机维修过程中的工作效率。但是在复杂多变的机场维修环境中,维修人员对目前的维修辅助设备提出更高的功能需求。另外技术的发展同样也促使维修辅助设备开发人员对设备的功能进行更新和精进。本论文正是应对在维修过程中维修人员对语音和视频通信的需求,在现有的维修辅助终端上实现VoIP(?)(?)H.264视频传输系统设计,满足维修人员在无线局域网通过免费语音通话协调彼此任务,以及将维修障碍通过视频实时传输到后台获取远程技术支持的需求。本论文所完成的主要工作和贡献如下： 1.配置Linux内核,添加摄像头驱动,制作内核镜像并完成内核的烧写。根据开发和应用需求选择合适的摄像头和无线局域网的组网协议。 2.完成维修辅助终端上VoIP客户端软件的设计,采用QT开发了VoIP客户端的操作界面,使用SIP等协议栈来实现VoIP客户端软件网络协议细节部分,并通过修改声卡驱动ALSA增加DMA缓存区触发中断的频率,达到减少通话中时延的目的,优化了VoIP通信质量。 3.完成H.264视频传输系统的设计,在设计中通过使用Linux内核视频设备驱动V4L2来采集ZC301摄像头输出的JPEG格式图像数据帧,编写JPEG解码代码实现对JPEG格式图像数据帧的解码。在解码结果进行显示的同时,系统将创建另一线程将对解码的视频数据帧进行H.264压缩编码,将压缩编码的结果用RTP协议打包发送到后台播放。 4.对所完成的VoIP客户端软件的功能进行测试,并对VoIP客户端语音通信的质量进行评估。
[Abstract]:In recent years, with the rapid development of software and hardware technology of embedded platform, the function of aircraft maintenance auxiliary equipment in China has been continuously expanded and strengthened, and the performance of various aspects has also been greatly improved. Effectively improve the maintenance staff in the aircraft maintenance process work efficiency. However, in the complex and changeable airport maintenance environment, maintenance personnel put forward higher functional requirements for the current maintenance auxiliary equipment. In addition, the development of technology also urges maintenance auxiliary equipment developers to update and improve the functions of the equipment. In this paper, the design of VoIP(?)H.264 video transmission system based on the existing maintenance assistant terminal is designed to meet the needs of the maintenance personnel for voice and video communication in the process of maintenance. It meets the need for maintenance personnel to coordinate each other's tasks through free voice calls in WLAN, and to transmit maintenance barriers to the background in real time through video to obtain remote technical support. The main work and contributions of this thesis are as follows: 1. Configure Linux kernel, add camera driver, make kernel image and finish kernel burning. Select appropriate camera and WLAN networking protocol according to development and application requirements. 2. The design of the VoIP client software on the maintenance assistant terminal is completed, the operation interface of the VoIP client is developed by using QT, and the details of the VoIP client software network protocol are realized by using the protocol stack such as SIP. By modifying the sound card to drive the ALSA to increase the frequency of the trigger interrupt in the DMA buffer, the delay in the call is reduced, and the quality of the VoIP communication is optimized. 3. The design of H.264 video transmission system is completed. In the design, the JPEG format image data frame of ZC301 camera is collected by using V4L2 driven by Linux kernel video device, and the JPEG decoding code is written to realize the decoding of JPEG format image data frame. While the decoding results are displayed, another thread will be created to compress and encode the decoded video data frames by H.264, and the compressed results will be packaged and sent to the background playing by RTP protocol. 4. The function of VoIP client software is tested, and the quality of VoIP client voice communication is evaluated.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP368.1;TN916.5

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